Daimler’s Mercedes-Benz unit announced in mid-June that the Mercedes AMG GT R supercar is the winner of the Association of German Engineers’ (VDI) first-ever award for vehicle lightweight design.
The VDI co-sponsored the new award with the Carbon Composites technology network, Daimler said in a release. The award was presented at a new auto industry lightweighting congress also organized by VDI and Carbon Composites.
The AMG GT-R, which starts at $157,000 in the U.S. market, features a number of unique lightweight solutions, chief being a one-piece carbon-fiber torque tube that, at about 30.6 lb (13.9 kg), is approximately 40% lighter than its three-piece aluminum counterpart in the standard AMG GT. In addition to its weight reduction, the company said the carbon-fiber torque tube also increases torsional rigidity by roughly 7.5%. The car’s driveshaft also is constructed of carbon-fiber reinforced polymer (CFRP), which cuts weight yet still is able to handle the twist of 519 lb·ft (700 N·m) and 577 hp developed by the car’s twin-turbocharged 4.0-L V8.
The AMG GT-R also employs two diagonal braces in the engine bay to increase front-end stiffness. These also are carbon fiber and weight approximately 50% less than steel counterparts. The car, meant primarily for racetrack use, has composite wheel-catch struts to help to deflect the front wheels toward the frame side members as a deliberate function of crash kinematics; these composite struts also are about 50% lighter than equivalent steel components. The company said it chose composite material rather than carbon fiber for catch struts because the composite material has the advantage of being significantly more deformable while still providing good material strength.
Mercedes said in a release, “The performance-oriented mixture of materials made up of magnesium, aluminum and carbon-fiber in the Mercedes-AMG GT R body is an example of how the weight and vehicle function of the Mercedes-AMG GT's aluminum body structure can be significantly improved through the targeted development of key components such as the roof, wings and crash, stiffening and aerodynamic elements as well as the torque tube with a carbon-intensive design – following the strict principle of having the right material in the right place.”
The company added that despite the GT R’s host of additional equipment, overall weight was reduced by nearly 28 lb (12.5 kg) compared with the standard AMG GT and “In addition, great importance was attached to the use of the latest technologies to prepare the cost-efficient use of carbon-fiber structures for larger volumes.”